중고 생활자전거 덜그럭 거리는 BB 유격 소음 해결하기,구형사각비비(어드저스터블비비)

There was a problem with BB (bottom bracket), which is commonly used in regular bicycles, so I tried to self-maintain it. It's a type of bb that you see a lot in Pixie bicycles and ordinary bicycles. It's also unfamiliar. I don't see it well these days, but I see it a lot on low-end bicycles. There are many cartridge square BBs, but you can also see a lot of adjustable (= spherical square ratio) ratios. Something weird and a guerrilla when pedaling